An X-ray gun that is! In a previous post, I described a collaborative project with the University of Michigan’s Kelsey Museum of Archaeology and the American Research Center in Egypt that sought to find a better means of excavating, stabilizing, and preserving beautifully-decorated, but incredibly fragile painted funerary artifacts. My role in the 2013 field season was to identify the materials of these coffins, statues, and wooden objects in order to better inform the approaches to their conservation. To do this, I needed to transport several scientific instruments to our field site in Abydos, Egypt. The IMA’s X-ray fluorescence (XRF) spectrometer, a.k.a. the X-ray gun, was one of those analytical tools, ideal for determining the elemental composition of the objects’ inorganic components (metals, minerals, stone) and small enough to be easily transported to a dig site lab (see Figure 1).

Figure 2. The Abydos dig house wet chemistry laboratory was used to test for proteins and polysaccharides in the paints used to decorate wooden funerary objects.

Operating a field lab in the desert requires a good deal of patience and creativity. Daily power outages, loss of the internet, and an omnipresent layer of dust can complicate analyses that would be quick and routine in the IMA’s state-of-the-art laboratories (see Figure 3). Stay tuned for the final installment describing the results of our research and some future research directions.

]]>http://www.imamuseum.org/blog/2013/11/22/the-ima-in-egypt-part-2-have-gun-will-travel/feed/0ima_egypt_fig1_112013ima_egypt_fig2_112013ima_egypt_fig3_112013The IMA in Egypt, Part 1: Science in the Sandhttp://www.imamuseum.org/blog/2013/10/15/the-ima-in-egypt-part-1/
http://www.imamuseum.org/blog/2013/10/15/the-ima-in-egypt-part-1/#commentsTue, 15 Oct 2013 18:42:57 +0000Greg Smithhttp://www.imamuseum.org/blog/?p=21057This spring I was part of a multi-disciplinary team tackling tricky archaeology in Egypt. The University of Michigan’s Kelsey Museum of Archaeology, under the direction of Egyptologist Dr. Janet Richards, excavates a famous cemetery site there, the Abydos Middle Cemetery (AMC). Abydos, positioned mid-way up the Nile River, was the burial site of Egypt’s earliest kings. Archaeologists commonly encounter beautifully-decorated funerary materials at the site, like the painted wood coffin shown below.

Figure 1. A painted coffin being unearthed at the Abydos Middle Cemetery excavation. Photo, S. Davis, courtesy of the Kelsey Museum of Archaeology.

Although these artifacts look well preserved, they are anything but! The wood has been attacked by fungi and termites to the point that only a brittle web of debris, insect frass (a.k.a. bug poop), and mud is holding it together. On top of this delicate matrix is an eggshell-thin layer of gesso and paint. How does one excavate and lift these fragile objects without crushing them? Archaeologists and conservators currently use a variety of methods to preserve these artifacts, but none work very well. The goal of this project was to find better approaches that could be used in the harsh desert conditions.

Figure 2. Dr. Smith descending into a cistern at Sepphoris, Israel.

So why me? To develop new conservation methods, the AMC conservators needed to understand the paints, pigments, and other materials present on the artifacts. Any new conservation treatment they designed would have to be sympathetic to these materials and not cause unexpected harm. Since no artifacts, or even samples of artifacts, are allowed to leave Egypt, the scientist and the necessary equipment would have to travel to Egypt with the project team. As it happens, I have a background in both chemistry and archaeology. While a chemistry graduate student at Duke University, I spent my summers excavating at Sepphoris in Israel’s Galilee region (Figure 2). With my conservation science expertise, the necessary portable instruments, and previous experience in archaeology, I was a natural fit.

The project team would spend several days in Cairo consulting with local conservators and visiting museums with artifacts similar to those at the field site. Then we were off to Abydos for a week of analysis and conservation trials. Our group, pictured below in front of the modern-day Abydos village, consisted of:

The MFA Boston’s Pamela Hatchfield, who has considerable expertise in the conservation of Egyptian antiquities

Dr. Robert Blanchette, professor of plant pathology and specialist in archaeological wood at the University of Minnesota

Mycologist Dr. Ahmed Abdel-Azeem, from Egypt’s University of Suez Canal, who has studied the fungi of North Africa

Stay tuned for part two of the story as I discuss working in the field!

]]>http://www.imamuseum.org/blog/2013/10/15/the-ima-in-egypt-part-1/feed/0Figure 1. A painted coffin being unearthed at the Abydos Middle Cemetery excavation. Photo, S. Davis, courtesy of the Kelsey Museum of Archaeology.ima_egypt_fig1_101513ima_egypt_fig2_101513ima_egypt_fig3_101513The Importance of the Superficial: Surfaces of Wooden Sculpture from Africahttp://www.imamuseum.org/blog/2012/02/09/the-importance-of-the-superficial-surfaces-of-wooden-sculpture-from-africa/
http://www.imamuseum.org/blog/2012/02/09/the-importance-of-the-superficial-surfaces-of-wooden-sculpture-from-africa/#commentsThu, 09 Feb 2012 18:51:08 +0000Kristen Adsithttp://www.imamuseum.org/blog/?p=18610As part of my work preparing for the reinstallation of the African galleries, I recently finished dusting the objects which are currently on view. Removing accumulated dust from artworks is essential, and not just because it looks bad. With time, dust can bond with, and encourage the deterioration of the surface of an artwork.

Dusting provided an opportunity to become acquainted with the wide range of surfaces that can be found on wooden sculpture from Africa. Given all the information one can get from these surfaces, this part of the project has been a visual and art historical education.

Under the dust, the surface observed can be one that the artist created. Yoruba sculptor Lamidi O. Fakeye, for example, highlighted the wood itself by leaving the surface of his mounted horseman unpainted and unvarnished.

Detail of Mounted Horseman by Lamidi O. Fakeye, which features a bare wooden surface.

Detail of the painted surface of a 20th century helmet for Bonu Amuen masker.

The forehead of the Deangle mask is covered with layers of ritually applied materials.

For many works, however, the observed surface is the result of the combination of the artist’s activity and the use of the object after it was created. Substances are often applied to painted wooden sculpture in Africa, however the material used and the reason for its application varies with the culture of origin of the piece. Because of this variety, materials on the surface of African sculpture can provide information that is valuable for understanding the ways in which people have interacted with it.

The forehead of this face mask for Deangle masker, for example, shows a rough texture that is distinct from the smooth surfaces elsewhere on the mask. This texture is the result of the application of many different sacrificial materials as an important part of its use in circumcision rituals.

This crocodile helmet mask made by the Nuna people of Burkina Faso is covered on the top of the head with chicken feathers and other remnants of sacrificial offerings.

Feathers and other ritual substances found on the Nuna crocodile helmet mask)

A third, key factor that contributes to the observed surface is the condition of the original and applied materials after aging. An example of a common condition than can develop with time is fatty acid bloom which results from the polymorphic transformation of fats or waxes. This condition is seen on this Tusian helmet mask.

Grey bloom on the Tusian helmet mask.

Analysis of the bloom can determine its chemical composition in order to help identify the applied material. The kind of materials applied to the surface can be diagnostic for the country or culture of origin for unknown works.

This education has already informed my activity in the next part of the redesign project–assessing the condition of artworks as part of the collection survey.

]]>http://www.imamuseum.org/blog/2012/02/09/the-importance-of-the-superficial-surfaces-of-wooden-sculpture-from-africa/feed/1Detail of Mounted Horseman by Lamidi O. Fakeye, which features a bare wooden surfaceDetail of the painted surface of a 20th century helmet for Bonu Amuen maskerThe forehead of the Deangle mask is covered with layers of ritually applied materialsFeathers and other ritual substances found on the Nuna crocodile helmet maskGrey bloom on the Tusian helmet mask